exploits people

Uber is really exploits people, you book a ride based how much they will charge you for the trip. When the ride is done and you get to your destination the Uber driver gives you a different amount and when you check it on the app then it changes when you stop. What if that person does not have that amount of course we book what we can afford. This is now happened to me on two different occasions. This is totally unacceptable ********* and by far unprofessional. Really up date your app to accommodate heavy traffic and not put a driver through this as some customers will not react nicely to this.